President Barack Obama announced Thursday he and First Lady Michelle Obama will make a landmark visit to Cuba on March 21-22, pledging to address human rights as America pursues a historic thaw with its former Cold War foe.

“Next month, I’ll travel to Cuba to advance our progress and efforts that can improve the lives of the Cuban people,” the US leader said in one of a series of tweets.

“We still have differences with the Cuban government that I will raise directly. America will always stand for human rights around the world.”

The Obamas will head from Cuba to Argentina on March 23-24, for a meeting with President Mauricio Macri who is opening up the country to foreign trade and investors after years of protectionism.

Obama’s visit to Cuba will be the first by a sitting US president since the island’s 1959 revolution.

The US leader sees ending five decades of isolationist US policy towards Cuba as a top foreign policy achievement, and had made clear that he wished to visit the island as he nears the end of his term in office.

The two countries restored diplomatic relations in July after a historic rapprochement between Obama and Cuban President Raul Castro the previous December.

Since then, new openings have been incremental with the US trade embargo still in place after more than half a century and little prospect of repeal under a Republican-controlled Congress.